Incidence of hypertension and risk of cardiovascular events among ethnic Chinese: report from a community-based cohort study in Taiwan

Background Hypertension confers risk on cardiovascular events; however, less is known concerning hypertension incidence among ethnic Chinese. The effect of prehypertension on new onset of hypertension and cardiovascular events is also unknown. Objectives To investigate the incidence of hypertension, risk factors and cardiovascular events in Taiwan. Design A prospective community-based cohort design. Setting and participants The Chin-Shan Community Cardiovascular Cohort consisted of 1703 men and 1899 women aged 35 years old and above, of homogeneous Chinese ethnicity, from 1990 to 2005. Main outcome measures Hypertension incidence rates, cardiovascular events. Results The patterns of adjusted cumulative incidence probability were curvilinear, increasing from 1% in the first period to 27% in the fourth period in normotensive subjects. The patterns among prehypertensives were from 4% in the first period to 59% in the fourth period. Women had an 18% lower risk of developing hypertension than men. The survival curves were distinctly different for different blood pressure categories (P < 0.001). Baseline blood pressure categories played important roles in predicting cardiovascular risks; the hazard risks of prehypertension and hypertension increased from 1.73 to 4.52, compared with baseline normotensive subjects. Conclusion The hypertension incidence rates among ethnic adult Chinese were high and were associated with obesity and metabolic syndrome status. Furthermore, the baseline prehypertension elicited significant risk of cardiovascular events in the community.